Improvement in cupola and other furnaces



MACKENZIE ISBELL.

' .Cupola furnace,

Patented May 29j 1866.1

ilwrrnn STATES PHILIP WV. MACKENZIE, OF JERSEY CITY, NEWIJERSEYAND CHARLES W.

FFICE0 ISBELL, OF NEW YORK, N. Y., ASSIGNORS TO THE SMITH St SAYRE MANU- FACTURING COMPANY, OF NEW YORK CITY.

IMPROVEMENT IN CUPOLA AND OTHER FURNACES.

Specification forming part of Letters Patent No. 55,204, dated May 29, 1866.

To all whom it may concern Be it known that we, PHILIP W. MAGKENZIE, of Jersey City, in the county of Hudson and State of New Jersey, and CHARLES W. ISBELL, of the city, county, and State of New York, have invented certain new and useful Improvements in Cupola and other Furnaces; and we do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawings, making a part of this specification, in which- Figure 1 is a vertical section of the lower portion of a cupola-furnace with our improvements. Fig. 2 is a horizontal section taken in the line m a" of Fig. 1.

Similar letters of reference indicate corresponding parts in both gures.

This invention may be considered as an improvement upon the invention of P.W. Mackenzie, patented August 25,1857, though it may be applied to cupola or other furnaces having an ordinary system of tuyeres.

It consists in providing two or more blastchambers arranged one above another around the lower part of the furnace, communicating with the furnace byseparate continuous or sheet tuyeres, or a series of jet-tuyeres at different distances from the bottom, and communicating with the blast-pipes through stop or throttle valves, for the purpose of introducing the blast to the furnace at a distance or distances above, as well as where it is commonly introduced. By this means we are enabled to effect a more perfect combustion of the gases in the lower part of the furnace, and preventintense combustion in the upper part, where it is injurious, and not only to melt the charge of metal more quickly, but also, by preventing or removing obstructions in the part of the furnace above where the blast is commonlyintroduced, to render the operation of the furnace continuous, instead of requiring it to be stopped every few hours, or after each heat has been run out.

To enable those skilled in the art to Linderstand the nature and construction of our invention, we will proceed to describe it with reference to the drawings.

Ais the body of the furnace, and a the boshes thereof, around the interior of which are situated the continuous tuyeres, through which the air passes into the furnace from holes or openings c, formed in the sheet-metal shell or casing e, which sustains the fire-brick of which the furnace itself is made.

The tuyeres may extend continuously all around the furnace, as shown at b b, to deliver the air in a sheet, or be constructed to deliver the air in jets, as shown at dd in Fig. 1. The inner upper edge of each tuyere overhangs the lower edge thereof, as shown in the said figure, in order to prevent the said tuyeres from being closed or choked up by the metal or fuel.

Placed around the lower portion of the furnace,or,in other words, surrounding the boshes, is an outer casing, 7l.. The space between this outer casing, h, and the furnace is divided into two or more chambers, it', by means of horizontal partitions m, extending entirely around the furnace. Each of these chambers t', except the lower one, communicates with one of the continuous tuyeres b by means of the openings c, or, in place thereof, with a series ot'jettuyeres d. Each of the chambers t' also communicates with the blast-pipe r by means of a short pipe or tube, n, the lowermost chamberz' communicating with the blast-pipe r by means of the pipe u', and a blast or current of air being forced downward in the blast-pipe r by any suitable means. Situated within the said blast-pipe, and near its lower end, is a valve, s, by which the blast can be shut off from the pipe n', and consequently from the lowermost chamber t'. A similar valve n is placed in each short pipe n, in order, when desired, to wholly or partially shut off the blast from their respective chambers z'.

Situated below the chambers t', and around the inner circumference of the outer casing, h, is a shoulder, B, between which and the bottom of the b'oshes there is a space, w, forming all around the furnace a continuous tuyere, through whichthe air enters from the lowermost chamber z', in the same manner as from the boshing-chamber in the furnace patented by P. W. Mackenzie, August 25, 1857, the enlarged space or chamber D, surrounded bythe shoulder B, answering to a corresponding space in the said patented furnace.

The furnace being charged inthe usual manner, the air passes inward from the lowermost chamber i, through the space or opening w, and enters underneath the charge in a broad sheet, and unites with the combustible gases below the charge at the same time that the air passing through the tuyeres enters the lower part of the furnace at various heights, the introduction of air in this manner insuring the combustion of all the combustible gases generated from the fuel in the lower part of the furnace, where the best effect of their combustion is obtained, instead of allowing them to rise and be burned in the upper part or stack, which, in the furnaces heretofore constructed, has not only occasioned in a great degree the waste of the heat generated by such combustion, but has greatly injured the upper portion of the furnace by burning out7 the same.

By turning the valves u a greater or less quantity of air may be admitted, or the air may be shut off entirely at any desirable height in the furnace, in order to increase the comA bustion at that part, as required in melting or burning out any obstruction that may find its way into the boshes, and thus enabling the furnace to be run without stopping for any desired length of time.

The furnace may be oval in its cross-section but this shape is not essential to the successful working of the invention, neither are the boshes absolutely necessary, as the air-chambers i, instead of being Within or under the boshes,as represented, may be arranged around its exterior, if desired.

What we claim as new, and desire to secure by Letters Patent, is-

1. The two or more separate chambers fi i, arranged one above another around the lower portion of the furnace, and each communicating with a separate tuyere or series of tuyeres, for conducting the air into the same furnace at different levels, substantially as herein set forth, for the purpose specified.

2. In combination with such air-chambers, the valves u fw, forming separate communications with the blast-pipe, for the purpose of admitting the air and controlling or stopping the admission thereof to the several chambers, substantially as herein described.

P. W. MAGKENZIE. CEAS. W. ISBELL.

Witnesses:

A. Ln CLERC, J. W. OooMBs. 

